Home-price forecasts for 2013 are on the rise.

J.P. Morgan Chase & Co. expects U.S. home prices to rise 3.4% in its base-case estimate and up to 9.7% in its most bullish scenario of economic growth. Standard & Poor’s, which rates private-issue mortgage bonds, on Friday said it expects a 5% rise in 2013.

The J.P. Morgan analysts boosted their base-case estimate from 1.5% after a convincing rise in the “net demand” for housing this year has surpassed 2 million homes for the first time since 2006, said John Sim, a strategist at the investment bank. Net demand is the pace of existing home sales minus the inventory of homes available for sale.